Move the blob LFS enabled lookup to the repository

Blobs can "look through" LFS pointers to the backing object, but only
if the blob belongs to a project or project wiki repository (for now).
This change moves the logic for that to the repository as a precursor
to making it static data.

app/models/blob.rb

@@ -129,7 +129,7 @@ class Blob < SimpleDelegator
 
   def external_storage_error?
     if external_storage == :lfs
-      !project&.lfs_enabled?
+      !repository.lfs_enabled?
     else
       false
     end

app/models/repository.rb

@@ -1120,6 +1120,17 @@ class Repository
     end
   end
 
+  # TODO: pass this in directly to `Blob` rather than delegating it to here
+  #
+  # https://gitlab.com/gitlab-org/gitlab/-/issues/201886
+  def lfs_enabled?
+    if container.is_a?(Project)
+      container.lfs_enabled?
+    else
+      false # LFS is not supported for snippet or group repositories
+    end
+  end
+
   private
 
   # TODO Genericize finder, later split this on finders by Ref or Oid

ee/spec/models/repository_spec.rb

@@ -219,6 +219,29 @@ describe Repository do
     end
   end
 
+  describe '#lfs_enabled? (design repositories)' do
+    let(:project) { create(:project, :design_repo, lfs_enabled: lfs_enabled) }
+    let(:repository) { project.design_repository }
+
+    before do
+      stub_lfs_setting(enabled: true)
+    end
+
+    subject { repository.lfs_enabled? }
+
+    context 'project has LFS disabled' do
+      let(:lfs_enabled) { false }
+
+      it { is_expected.to be_falsy }
+    end
+
+    context 'project has LFS enabled' do
+      let(:lfs_enabled) { true }
+
+      it { is_expected.to be_truthy }
+    end
+  end
+
   describe '#upstream_branch_name' do
     let(:pull_mirror_branch_prefix) { 'upstream/' }
     let(:branch_name) { 'upstream/master' }

spec/models/repository_spec.rb

@@ -2874,4 +2874,64 @@ describe Repository do
       expect(repository.submodule_links).to be_a(Gitlab::SubmoduleLinks)
     end
   end
+
+  describe '#lfs_enabled?' do
+    let_it_be(:project) { create(:project, :repository, lfs_enabled: true) }
+
+    subject { repository.lfs_enabled? }
+
+    context 'for a project repository' do
+      let(:repository) { project.repository }
+
+      it 'returns true when LFS is enabled' do
+        stub_lfs_setting(enabled: true)
+
+        is_expected.to be_truthy
+      end
+
+      it 'returns false when LFS is disabled' do
+        stub_lfs_setting(enabled: false)
+
+        is_expected.to be_falsy
+      end
+    end
+
+    context 'for a project wiki repository' do
+      let(:repository) { project.wiki.repository }
+
+      it 'returns true when LFS is enabled' do
+        stub_lfs_setting(enabled: true)
+
+        is_expected.to be_truthy
+      end
+
+      it 'returns false when LFS is disabled' do
+        stub_lfs_setting(enabled: false)
+
+        is_expected.to be_falsy
+      end
+    end
+
+    context 'for a project snippet repository' do
+      let(:snippet) { create(:project_snippet, project: project) }
+      let(:repository) { snippet.repository }
+
+      it 'returns false when LFS is enabled' do
+        stub_lfs_setting(enabled: true)
+
+        is_expected.to be_falsy
+      end
+    end
+
+    context 'for a personal snippet repository' do
+      let(:snippet) { create(:personal_snippet) }
+      let(:repository) { snippet.repository }
+
+      it 'returns false when LFS is enabled' do
+        stub_lfs_setting(enabled: true)
+
+        is_expected.to be_falsy
+      end
+    end
+  end
 end